Ultimate Strength Of Stiffened Plates Research Articles

Numerical Investigation on the Residual Ultimate Strength of Central-Cracked Stiffened Plates under Tensile and Bending Loads Using XFEM

The present paper aims to study the crack propagating behavior of a stiffened plate under tensile and bending displacement load loads. The extended finite element method (XFEM) is used to analyze the residual ultimate strength of stiffened plates with a central crack. The quasi-static crack growth process is simulated by software ABAQUS. The validity of the grid is validated by the plate with a central crack. The numerical method is validated by comparing the fatigue crack growth rate of the round compact tension specimen (RCT) results of the extended finite element with experiment values. Influential parameters, including the size of the stiffened plates, heights of the stiffeners is varied, and uniaxial tensile and four-point bending models are analyzed. The results show that ultimate strength is reduced by the action of tensile and bending loads. The bottom plate and stiffener are destroyed with crack propagation, successively. With the increase in stiffener height, the crack resistance will also increase, thus restraining the central crack growth of stiffened plates.

Experimental and Numerical Investigations of Ultimate Strength of Imperfect Stiffened Plates of Different Slenderness

Abstract The objective of this study is to analyse the behaviour of compressed stiffened plates of different slenderness using experimental and numerical methods. The presented results are part of a long-term project to investigate the ultimate strength of geometrically imperfect structures subjected to different degradation phenomena, including corrosion degradation and locked cracks. Several specimens were subjected to a uniaxial compressive force, and the most important quantities related to the structural behaviour were captured and analysed. A finite element model, accounting for material and geometrical nonlinearities and initial geometrical imperfections, was developed using the commercial software ANSYS. The residual welding-induced stresses were measured in the middle cross-section for two specimens. The initial imperfection was identified by employing a close-range photogrammetry approach. It was concluded that the numerical analyses, based on the finite element model, predict the ultimate strength of stiffened plates accurately, although some deviations were also observed. The detailed analysis with the indication of possible uncertainty is presented, and several conclusions are derived.

Estimation of Ultimate Strength of Continuous Stiffened Plates under Thrust

A simplified method to calculate the ultimate strength of a continuous stiffened plate under uniaxial thrust is presented. The proposed method is characterised as follows : (1) A continuous stiffened plate is idealised as a double-span beam-column model having an effective width of plate to consider the interaction between adjacent spans.(2) For flat-bar stiffeners, the reduction in axial stiffness due to the interactive local buckling between plate and stiffener is taken into account by introducing a concept of effective thickness.(3) Both effective width of a plate and effective thickness of a flat-bar stiffener are expressed as a function of a thrust load to evaluate the effective cross-section of a stiffened plate at ultimate strength accurately.(4) The influence of torsional stiffness of a stiffener on the local buckling strength of a plate and the resistance of a plate against the rotation of a stiffener are considered as plate/stiffener interactions.(5) The ultimate strength of a stiffened plate is examined based on the initial yield criterion considering both bending and warping stresses.A series of ultimate-strength estimates has been performed for the continuous stiffened plates with flat-bar, angle-bar and tee-bar stiffeners, and the validity and usefulness of the proposed method have been demonstrated through the comparison with the results of elastoplastic large-deflection FEM analyses.